A fuel cell consists of a fuel electrode, an oxidizer electrode and electrolyte provided between them. Fuel is supplied to the fuel electrode, an oxidizer is supplied to the oxidizer electrode, and the fuel cell generates power by electrochemical reactions. Although hydrogen is generally used as a fuel, active development of direct type fuel cells has been seen recent years. The direct type fuel cells directly use methanol as a fuel, which is inexpensive and easy to handle.
When hydrogen is used as a fuel, the reaction at the fuel electrode is given by Formula (1):3H2→6H++6e−.  (1)
When methanol is used as a fuel, the reaction at the fuel electrode is given by Formula (2):CH3OH+H2O→6H++CO2+6e−.  (2)
In both cases, the reaction at the oxidizer electrode is given by Formula (3):3/2O2+6H++6e−→3H2O.  (3)
Japanese Patent Application Laid-Open No. 2003-92128 (Patent Document 1) discloses an example in which when a fuel cell is used as a power source of a portable electronic appliance, a fuel cartridge is used for supplying fuel to the fuel cell.